Multiphase High-Voltage Transformer Layout for Low Ripple Switching

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Solution Overview

Problem

High-voltage generators face challenges in achieving a small output ripple and fast voltage switching without increasing switching frequency or output capacitance, which affects performance in applications like MRI devices.

Innovation Solution

A high-voltage transformer with a magnetic core assembly and multi-phase windings, where M primary windings are interconnected and N layers of secondary windings are concentrically wound, combined with a rectifier circuit and multi-phase inverter, to achieve reduced ripple and faster switching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If the switching frequency is increased to reduce output ripple, then the output ripple is reduced, but the switching losses increase

Engineering Contradiction:
Improveoutput rippleVSAvoidswitching losses
Core Design Contradiction:
Object-generated harmful factorsVSLoss of energy

Solution Approach 1:

The patent divides the single-phase system into multi-phase parallel circuits. By segmenting the power conversion into multiple phases (e.g., three-phase), the output ripple is reduced through phase cancellation effects while maintaining lower switching frequencies, thus avoiding increased switching losses.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the operational parameters by introducing multi-phase configurations with specific phase shifts. This parameter change allows the system to achieve lower output ripple through constructive interference of ripple components from different phases, eliminating the need to increase switching frequency.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If the output capacitance is increased to reduce output ripple, then the output ripple is reduced, but the generator size increases

Engineering Contradiction:
Improveoutput rippleVSAvoidgenerator size
Core Design Contradiction:
Object-generated harmful factorsVSVolume of stationary object

Solution Approach 1:

The patent segments the output filtering function across multiple parallel phases. Each phase uses smaller capacitance, but the combined effect of multiple phases provides superior ripple reduction compared to a single large capacitor, thus reducing overall generator size.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the capacitance parameter distribution by using multiple smaller capacitors in parallel phases instead of one large capacitor. This parameter redistribution achieves the same or better ripple filtration effect while reducing the total volume required.

Inventive Principle:
Principle #35Parameter changes

3Speed

If the switching frequency is increased to achieve fast voltage switching, then the voltage switching speed is improved, but the switching losses increase

Engineering Contradiction:
Improvevoltage switching speedVSAvoidswitching losses
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

The patent divides the voltage switching function across multiple parallel phases, allowing each phase to operate at lower switching frequencies while achieving fast overall voltage response through the combined effect of multiple phases.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the switching frequency parameter by operating multiple phases at lower frequencies with appropriate phase shifts, achieving fast voltage switching response without the penalty of high switching losses associated with single high-frequency operation.

Inventive Principle:
Principle #35Parameter changes

4Volume of stationary object

If the generator size is reduced, then the device complexity is reduced, but the leakage inductance parameters become inconsistent

Engineering Contradiction:
Improvegenerator sizeVSAvoidleakage inductance parameters consistency
Core Design Contradiction:
Volume of stationary objectVSStability of the object's composition

Solution Approach 1:

The patent segments the transformer into multiple parallel phases with identical, standardized designs. This segmentation allows each phase to be independently optimized with consistent leakage inductance parameters, while the overall generator size is reduced through efficient multi-phase integration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by ensuring each phase has identical leakage inductance characteristics through standardized design. This local consistency in parameter quality across all phases maintains stable composition while allowing compact generator sizing.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution results in smaller output ripple and faster voltage switching, reducing switching losses and generator size while maintaining consistent leakage inductance parameters.

Implementation Method 1

a high-voltage transformer configured to receive an input of M-phase AC power

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The magnetic core assembly includes M magnetic pillar sets. The M primary windings are respectively wound on the M magnetic pillar sets

Methodology Applied
Scientific EffectMagnetic flux concentration: Magnetic Field

Implementation Method 3

The rectifier circuit includes N rectifier modules. Input terminals of the i-th rectifier module are connected to the M secondary windings of the i-th layer

Methodology Applied
Scientific EffectRectification: Diode

Data Source

PatentEP4579697A1High-voltage generator and x-ray system
Publication Date: 2025.07.02 SHANGHAI UNITED IMAGING HEALTHCARE
  • EP4579697A1 patent drawingFigure 1~2
  • EP4579697A1 patent drawingFigure 3~4
  • EP4579697A1 patent drawingFigure 5~6

AI summary

The present disclosure provides a high-voltage generator, which includes a high-voltage transformer. The high-voltage transformer includes M magnetic core assembly, M primary windings, and M*N secondary windings. The magnetic core assembly includes M magnetic pillar sets. The M primary windings are respectively wound on the M magnetic pillar sets. N layers of the secondary windings are concentrically wound on each of the primary windings, and M, N are positive integers. The M primary windings are configured such that first ends of the M primary windings receive the input of the M-phase AC power and second ends of the M primary windings are interconnected.